1. Field of the Invention
The present invention relates to a cutting tool having a metal body and a cemented carbide cutting tip secured to the metal body, and also relates to a method for making the cutting tool.
2. Description of the Related Arts
In a cutting tool having a steel metal body and a cemented carbide cutting tip secured to the metal body, the cutting tip is generally secured to the metal body by way of brazing materials such as a silver alloy or similar. In such a cutting tool having a brazed cutting tip, the hardness of the metal body may be lacking due to the heat caused during the brazing process because the metal body is annealed by the heat. Further, the possibility exists that the cutting tip is detached from the metal body where a load to the cutting tip is large. Taking into account the above, as shown in the Japanese unexamined patent publication No. Sho 63-43789 and the Japanese unexamined patent publication No. Hei 4-52181, a cutting tool has been provided which has a metal body and a cutting tip melt-welded to the metal body by applying a high energy beam such as an electron beam or a laser beam or similar. Such a cutting tool can stand considerably heavier load as compared to the above-mentioned cutting tool having a brazed cutting tip.
However, even in the cutting tool having a cutting tip secured to the metal body by applying a high energy beam, cracks may be generated at edge portions of the securing portion between the cutting tip and the metal body when the load exceeds a certain level. Thus, further improvements to the cutting tool can be been expected.